Sioux City, IA: US-20 Route Evolution

The original route used the 1896 bridge over the Missouri River

20 Overview

Exploring Historic Route 20 posted

One of the best parts of a Route 20 road trip is finding and following the original 1926 alignments of the highway as they were originally intended.

Luckily for us, the State of Iowa did an amazing job at making maps, even in 1926 to show us where Highway 20 went through Sioux City, Iowa. 

Today, if you follow just the black and white signs, you’ll be on a 4 lane highway and even interstate highway.   

It can take some maneuvering, and careful attention to follow, but you are rewarded with a beautiful downtown, riverfront and a ton of history.

Let's start with the big picture. On the east side, the original route used the dashed line. I presume it wiggles around near Sioux City because of hills. This is the road that enters Sioux City on Correctionville Road. Gordon Drive must have been built when they built the straight alignment for US-20.

1955 Sioux City Quad @ 250,000

This map shows the original route based on the detailed topo map below. Note how the north/south part of the route through South Sioux City became the commercial district of that town.

Google Earth, Aug 2025 plus Paint

The details about how the route got between 4th Street and Correctionville Road on the east side of downtown are confusing. I could not find some of the roads on the above posted detail map. Not only have the roads changed since 1926, they have changed since 1976. And Floyd River has moved! (I wonder when the river was channelized.) Back in 1977, 4th Street was intact to almost Floyd Cemetery and 3th Street did not go through to Fairmount Street. So I followed this map where 4th Street makes it almost to the cemetery, then uses a little diagonal road to get down to Fairmount.

1976 Sioux City South and 1964 Sergeant Bluff Quads @ 24,000

The route after US-20 entered town at Gordon Drive is easy to follow because Google Maps labels most of it as BUS-20. The big change, in addition to building Gordon Driver, is that it shares "Highway 77" on the west side of the metro area. In 1981, BUS-20 switched to use the Siouxland Veterans Memorial Bridge.

Google Earth, Aug 2025 plus Paint

Google Maps doesn't label it, but I'm sure that today's US-20 route goes south at US-75 and then continues West on I-129. It continues West where US-75 turns South. According to the map at the top, it was rerouted to expressways around the metro area in 1979.